Agglutination of Sea Urchin Eggs and Sperm by Basic Proteins

Summary

The agglutination of sea urchin eggs and sperm by basic protein extracts of homologous and unrelated sperm (reported by Hultin, ^5,6) is confirmed. Experiments are cited which show that antifertilizin, another egg agglutinin obtainable from sperm, is not present in or identical with the egg agglutinating basic protein fraction of sea urchin sperm as Hultin claims. Thus two distinct epp agglutinins are obtainable from whole sperm. One of these, antifertilizin, is obtained by heating, freeze-thawing or pH 3 extraction (Frank,⁷ Tyler,^8,10); the other, a basic protein(s), is obtained by pH 1 extraction of sperm.